DEGRADATION OF RUTIN BY ASPERGILLUS FLAVUS. FACTORS AFFECTING PRODUCTION OF THE ENZYME SYSTEM

1961 ◽  
Vol 7 (1) ◽  
pp. 33-44 ◽  
Author(s):  
D. W. S. Westlake ◽  
F. J. Simpson
Keyword(s):  
Calcium Carbonate ◽  
Aspergillus Flavus ◽  
Extracellular Enzymes ◽  
Enzyme System ◽  
Synthetic Medium ◽  
Extracellular Enzyme ◽  
Factors Affecting ◽  
Higher Temperature

A synthetic medium containing 0.4% rutin, 0.3% (NH4)2HPO4, 0.1% KH2PO4, 0.1% MgCl2∙6H2O, and 0.8% (NH4)2SO4was developed for the production of the extracellular enzyme system that degrades rutin. The total amount of the enzyme system produced is approximately the same between 25 and 35 °C but the rate is more rapid at the higher temperature. Aeration is necessary both for synthesis and for excretion into the medium, excretion apparently being more sensitive than synthesis. Magnesium is required for growth and sulphate for release of the enzyme system into the medium. Calcium carbonate depresses both growth and production. The medium has been successfully employed for production in 5-gallon fermentors of the extracellular enzymes that degrade rutin.

FACTORS AFFECTING THE GROWTH OF MYCOBACTERIUM MARINUM

1966 ◽  
Vol 12 (4) ◽  
pp. 715-723 ◽  
Author(s):  
Barbara Newton Trentham ◽  
Ilda McVeigh
Keyword(s):  
Oleic Acid ◽  
Glutamic Acid ◽  
Synthetic Medium ◽  
Tween 80 ◽  
Mycobacterium Marinum ◽  
Single Source ◽  
Inhibitory Effects ◽  
Factors Affecting ◽  
Higher Temperature

The two strains of Mycobacterium marinum Aronson (Mycobacterium balnei Nordén) investigated were able to grow in a CO2-enriched atmosphere (5 and 10% CO2) in media in which they failed to grow or grew poorly when incubated in air. One strain grew better at 37 °C in cultures incubated in a CO2-enriched atmosphere than it did in cultures incubated at 30 °C either in air or in the CO2-enriched atmosphere. The growth of the second strain was stimulated markedly by CO2 during incubation at 30 °C, and it was able to grow at 37 °C when supplied with additional CO2, although not as well as at 30 °C. Glutamic acid was the best single source of nitrogen for the growth of each strain, but one strain grew almost as well with asparagine. Oleic acid exerted inhibitory effects on the growth of each strain in a synthetic medium at 37 °C, whereas it produced a slight stimulatory effect on their growth at 30 °C. Tween 80 inhibited the growth of each strain in the synthetic medium at both 30 and 37 °C, but the degree of inhibition was greater at the higher temperature. Methods for obtaining uniform suspensions of the cells are described.

An evaluation of fungal enzymes for the solubilization of wheat bran constituents

1970 ◽  
Vol 16 (3) ◽  
pp. 139-146 ◽  
Author(s):  
T. S. Neudoerffer ◽  
R. E. Smith
Keyword(s):  
Wheat Bran ◽  
Enzyme Preparation ◽  
Extracellular Enzymes ◽  
Enzyme System ◽  
Trichoderma Viride ◽  
Extracellular Enzyme ◽  
Insoluble Fraction ◽  
Fungal Enzymes ◽  
Crude Enzyme Preparation ◽  
Better Than

Cellulolytic fungi were evaluated for their ability to use wheat bran and produce extracellular enzymes capable of solubilizing carbohydrate and protein fractions from wheat bran. Trichurus cylindricus grew better than all other organisms tested and excreted an extracellular enzyme system which was distinguished by high C1 and Cx cellulase and proteolytic activity. Evidence was also obtained for the existence of a partially extracellular lignolytic enzyme system. The extracellular enzyme system possessed high activity towards wheat bran and the dilute enzyme was able to bring about a 28% weight loss from the insoluble fraction of the wheat bran substrate in 24 h. The extracellular enzyme system from Trichoderma viride and Myrothecium verrucaria were also studied but they were found to be inferior to those of Trichurus cylindricus for the solubilization of wheat bran. However, the crude enzyme preparation from Trichurus cylindricus had a lower activity towards purified cellulose than the enzyme from Trichoderma viride.

Enzyme system of Clostridium stercorarium for hydrolysis of arabinoxylan: reconstitution of the in vivo system from recombinant enzymes

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2257-2266 ◽  
Author(s):  
Helmuth Adelsberger ◽  
Christian Hertel ◽  
Erich Glawischnig ◽  
Vladimir V. Zverlov ◽  
Wolfgang H. Schwarz
Keyword(s):  
Extracellular Enzymes ◽  
Enzyme System ◽  
Thermophilic Bacterium ◽  
Recombinant Enzymes ◽  
Type Mode ◽  
Complete Set ◽  
First Time ◽  
Hydrolysis Of

Four extracellular enzymes of the thermophilic bacterium Clostridium stercorarium are involved in the depolymerization of de-esterified arabinoxylan: Xyn11A, Xyn10C, Bxl3B, and Arf51B. They were identified in a collection of eight clones producing enzymes hydrolysing xylan (xynA, xynB, xynC), β-xyloside (bxlA, bxlB, bglZ) and α-arabinofuranoside (arfA, arfB). The modular enzymes Xyn11A and Xyn10C represent the major xylanases in the culture supernatant of C. stercorarium. Both hydrolyse arabinoxylan in an endo-type mode, but differ in the pattern of the oligosaccharides produced. Of the glycosidases, Bxl3B degrades xylobiose and xylooligosaccharides to xylose, and Arf51B is able to release arabinose residues from de-esterified arabinoxylan and from the oligosaccharides generated. The other glycosidases either did not attack or only marginally attacked these oligosaccharides. Significantly more xylanase and xylosidase activity was produced during growth on xylose and xylan. This is believed to be the first time that, in a single thermophilic micro-organism, the complete set of enzymes (as well as the respective genes) to completely hydrolyse de-esterified arabinoxylan to its monomeric sugar constituents, xylose and arabinose, has been identified and the enzymes produced in vivo. The active enzyme system was reconstituted in vitro from recombinant enzymes.

scholarly journals Extracellular hydrolytic enzyme production by proteolytic bacteria from the Antarctic

2013 ◽  
Vol 34 (3) ◽  
pp. 253-267 ◽  
Author(s):  
Mauro Tropeano ◽  
Susana Vázquez ◽  
Silvia Coria ◽  
Adrián Turjanski ◽  
Daniel Cicero ◽  
...  
Keyword(s):  
Extracellular Enzymes ◽  
Restriction Analysis ◽  
Hydrolytic Enzyme ◽  
Hydrolytic Enzymes ◽  
Extracellular Enzyme ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Potter Cove ◽  
Starting Point ◽  
Dna Restriction

AbstractCold−adapted marine bacteria producing extracellular hydrolytic enzymes are important for their industrial application and play a key role in degradation of particulate organic matter in their natural environment. In this work, members of a previously−obtained protease−producing bacterial collection isolated from different marine sources from Potter Cove (King George Island, South Shetlands) were taxonomically identified and screened for their ability to produce other economically relevant enzymes. Eighty−eight proteolytic bacterial isolates were grouped into 25 phylotypes based on their Amplified Ribosomal DNA Restriction Analysis profiles. The sequencing of the 16S rRNA genes from representative isolates of the phylotypes showed that the predominant culturable protease−producing bacteria belonged to the class Gammaproteobacteria and were affiliated to the genera Pseudomonas, Shewanella, Colwellia, and Pseudoalteromonas, the latter being the predominant group (64% of isolates). In addition, members of the classes Actinobacteria, Bacilli and Flavobacteria were found. Among the 88 isolates screened we detected producers of amylases (21), pectinases (67), cellulases (53), CM−cellulases (68), xylanases (55) and agarases (57). More than 85% of the isolates showed at least one of the extracellular enzymatic activities tested, with some of them producing up to six extracellular enzymes. Our results confirmed that using selective conditions to isolate producers of one extracellular enzyme activity increases the probability of recovering bacteria that will also produce additional extracellular enzymes. This finding establishes a starting point for future programs oriented to the prospecting for biomolecules in Antarctica.

scholarly journals Response of <i>Nodularia spumigena</i> to <i>p</i>CO<sub>2</sub> – Part 2: Exudation and extracellular enzyme activities

2013 ◽  
Vol 10 (1) ◽  
pp. 567-582 ◽  
Author(s):  
S. Endres ◽  
J. Unger ◽  
N. Wannicke ◽  
M. Nausch ◽  
M. Voss ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Organic Matter ◽  
Enzyme Activities ◽  
Extracellular Enzymes ◽  
Extracellular Enzyme ◽  
High Pco2 ◽  
Nodularia Spumigena ◽  
Extracellular Enzyme Activities ◽  
Pco2 Treatment ◽  
Co2 Concentrations

Abstract. The filamentous and diazotrophic cyanobacterium Nodularia spumigena plays a major role in the productivity of the Baltic Sea as it forms extensive blooms regularly. Under phosphorus limiting conditions Nodularia spumigena have a high enzyme affinity for dissolved organic phosphorus (DOP) by production and release of alkaline phosphatase. Additionally, they are able to degrade proteinaceous compounds by expressing the extracellular enzyme leucine aminopeptidase. As atmospheric CO2 concentrations are increasing, we expect marine phytoplankton to experience changes in several environmental parameters, including pH, temperature, and nutrient availability. The aim of this study was to investigate the combined effect of CO2-induced changes in seawater carbonate chemistry and of phosphate deficiency on the exudation of organic matter, and its subsequent recycling by extracellular enzymes in a Nodularia spumigena culture. Batch cultures of Nodularia spumigena were grown for 15 days under aeration with low (180 μatm), medium (380 μatm), and high (780 μatm) CO2 concentrations. Obtained pCO2 levels in the treatments were on median 315, 353, and 548 μatm CO2, respectively. Extracellular enzyme activities as well as changes in organic and inorganic compound concentrations were monitored. CO2 treatment–related effects were identified for cyanobacterial growth, which in turn influenced the concentration of mucinous substances and the recycling of organic matter by extracellular enzymes. Biomass production was increased by 56.5% and 90.7% in the medium and high pCO2 treatment, respectively, compared to the low pCO2 treatment. In total, significantly more mucinous substances accumulated in the high pCO2 treatment, reaching 363 μg Xeq L−1 compared to 269 μg Xeq L−1 in the low pCO2 treatment. However, cell-specific rates did not change. After phosphate depletion, the acquisition of P from DOP by alkaline phosphatase was significantly enhanced. Alkaline phosphatase activities were increased by factor 1.64 and 2.25, respectively, in the medium and high compared to the low pCO2 treatment. We hypothesise from our results that Nodularia spumigena can grow faster under elevated pCO2 by enhancing the recycling of organic matter to acquire nutrients.

FACTORS AFFECTING THE COLD SURVIVAL OF WINTER CEREALS

1977 ◽  
Vol 57 (1) ◽  
pp. 213-219 ◽  
Author(s):  
L. V. GUSTA ◽  
D. B. FOWLER
Keyword(s):  
Winter Wheat ◽  
Cold Tolerance ◽  
Winter Rye ◽  
Factors Affecting ◽  
Winter Cereals ◽  
Higher Temperature ◽  
Thawing And Freezing Cycles

Several parameters affecting cold tolerance of winter cereals in artificial freeze tests were examined. Supercooling followed by freezing resulted in death occurring at a higher temperature than when freezing was initiated just below 0 C. The cold tolerance of fully acclimated crowns of winter wheat and a winter rye were reduced an average of 5 C after two thawing and freezing cycles. The duration of freezing in artificial freeze tests has a significant effect on the LD50 of winter cereals. Rapid thawing (2–4 C/min) resulted in death occurring at a higher temperature than slow thawing (0.5–2 C/h).

Production and control of extracellular enzymes in Micrococcus sodonensis

1974 ◽  
Vol 20 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Cecily Mills ◽  
J. N. Campbell
Keyword(s):  
Alkaline Phosphatase ◽  
Inorganic Phosphate ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Synthetic Medium ◽  
Culture Conditions ◽  
The Other ◽  
Organic Nutrients ◽  
And Control ◽  
Logarithmic Growth

Micrococcus sodonensis has been shown to produce several extracellular enzymes: an alkaline phosphatase, at least two forms of phosphodiesterase, a 5′-nucleotidase, and an alkaline proteinase. The quantitative release of these enzymes into the culture medium during logarithmic growth under all the various culture conditions tested indicates that these enzymes are truly extracellular in nature. Inorganic phosphate repressed the production of the alkaline phosphatase in synthetic as well as in complex media, whereas, the repression of the production of active diesterase and 5′-nucleotidase by inorganic phosphate was partly reversed by the addition of supplemental organic nutrients to the culture medium. Proteinase production was independent of the culture conditions used. A mutant strain of M. sodonensis with an altered production of diesterase was obtained; the other extracellular enzymes were unaffected. These results suggest that the extracellular enzymes of M. sodonensis are not produced in a pleiotropic fashion since the level of one of the enzymes can be changed without affecting a corresponding change in the levels of the other enzymes. An extracellular high molecular weight carbohydrate fraction was shown to be produced by M. sodonensis in synthetic medium. The fraction was also shown to contain glycoprotein.

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